The Polish capital braced for flooding today and prepared for the evacuation of thousands of people as waters rose on the Vistula River in central Warsaw, according to dpa. Six people have died in flooding since Monday. Water levels along the Vistula rose to 5.6 metres as a wave of flood water moved up the river after days of heavy rain in southern Poland. Water levels would reach their highest point Friday afternoon, officials said. Those levels were expected to exceed the emergency level of 6.5 metres, reaching a peak of 7.8 metres. City officials assured residents they were prepared for up to 8 metres of water, but thousands would have to be evacuated if the waters rose higher. The Warsaw Zoo was considered at particular risk, as barriers were placed there Thursday to hold back flood waters. Warsaw Mayor Hanna Gronkiewicz-Waltz said the city was well- prepared and had some 200,000 bags of sand at the ready. Soldiers were also on call, a city official said. Residents were seen stocking up on bread and staples at a market in Saska Kepa, a neighborhood by the Vistula. Warsaw officials appealed to residents near the river banks to prepare for flooding and possible power outages, and to secure their valuables and to park their cars away from the area. Rescue helicopters airlifted several people earlier Thursday from villages near Sandomierz, in south-western Poland, after flood waters there reached up to the roofs, TVN 24 reported. Acting President Bronislaw Komorowski said he would propose regulations Thursday that will make it easier for the government to buy land needed to build anti-flood infrastructure. "It's a problem for Poland that interest in anti-flood safety lasts about as long as the flood itself," or as long as repairing the flood's damage, Komorowski told reporters. Some 20,000 households were left without power in the Opole Province, southern Poland, as some 37 schools there were closed amid flooding. Nearly 1,500 soldiers were working in rescue efforts across six provinces in southern and central Poland, using some 58 boats and amphibious carriers, officials said. Prime Minister Donald Tusk said late Wednesday that losses from the flood so far could total more than 2 billion euros (2.5 billion dollars). Tusk said that water levels along the Vistula River were the highest in 160 years. Tusk reiterated that he would not declare a state of emergency. A state of emergency would push back the presidential elections slated for June 20. By law, presidential elections must be held 90 days after the end of a state of emergency.